Electric steam generator



Patented Nov. 2, 1937 UNITED STATES PATENT OFFlCE tric Steam SterilizingCompany, Inc.,

New

York, N. Y., a corporation of Delaware Application March 31, 1936,Serial No. 71,883

-11 Claims.

This invention is directed to an improvement in electric steamgenerators, and has for one of 'its vobjects the provision of such anapparatus which will be compact, involve no moving parts, relativelyinexpensive to manufacture and of 'long life.

Generally speaking my invention provides an apparatus in Whichfeedwateris supplied Vto the top of the apparatus, Vwhile the steam outlet Vmaybe either at the top or bottom of the apparatus.

` My improved apparatus embodies a metal mass into which/the heatingvelement is cast, this mass surrounding the evaporating surface, whichtakes the form of a metal casting extending into the metal mass andprovided with a downwardly inclined groove extending helically about theperiphery of the casting, means being provided for conducting thegenerated steam upwardly through the center of the generator to anoutlet near the top thereof,

Means are provided adjacent the feedwater inlet for `automatictemperature control of the metal mass, this 'device comprising athermostat functioning to maintain the metal mass within a predeterminedtemperature range and to close an electric circuit to the heatingelement `when feedwater is supplied to the apparatus.

I alzso vprovide in my improved apparatus for reducing the thermalconductivity of the metal mass adjacent thefeedwater inlet, which aidsin reducing objectionable bumping and surging when my apparatus is inoperation.

In the accompanying drawing:

Fig. l is a sectional elevational view of .an embodiment of myinvention;

Fig. 2 is a plan view;

Fig. 3 is a section on the line 3 3 of Fig. .1; and

Fig. 4 is a sectional elevational view of the temperature controlapparatus.

Referring to the drawing in detail, I designates a mass of metal,cylindrical, for example, in shape, provided with a groove 2 extendinghelieally of the casting. This metal mass is slightly tapered and isenclosed by a pressure proof metal shell 3 in such a manner that adownwardly exftending channel for the iluid to be evaporated isyprovided. Means are provided for conducting the generated steamupwardly to an outlet near the top of the shell '3 as will be'broughtout hereinafter.

The top of the shell '3 is provided with a'lower wall 4 and upper wall 5spaced slightly from each Vother to provide for the oW of Water enteringthe apparatus through inlet 6 before the same enterstheevaporating'channel above referred to.

These walls are so shaped as to provide a Well 'I in which is mountedthe thermostatic control device shown in Fig. 4 and which will bedescribed in detail hereinafter. By passing the feedwater between thetwo walls I and 5 the thermostat will be cooled down to insure closingof the electric circuit of the heating element of my generator wheneverieedwater is supplied.

The general shape of the shell 3 is cylindrical and tap-ered and it tsinto a hole of te same taper in the heater casting. This heater eastingcomprises a. metal mass S into which is east the heating element 9.

This arrangement provides goed contact between all heat conducting partsand insures excellent heat conductivity.

The evaporating surface provided by the arrangement of the groovedcasting I and shell 3 is in communication with a central channel iii inthe casting to the upper end of which is connected the steam outlettubing I I. This tubing is led around the assembled parts for aboutthree quarters of a turn to relieve any stresses set up by temperaturechanges and is then led to the outside of the apparatus. This tubing isinterrupted intermediate its ends for the insertion of pyrex glasstubing i2 to reduce heat losses caused by a continuous copper tubing.

The shell 3, mass I and the thermostatic control are held in place bycross member lil and screws I5.

l5 designates a collar slipped over shell 3 before the same is placed inposition. This collar is provided with screws I'l and when the same arescrewed down collar IS will be raised to lift shell 3, metal mass I andthermostatic control apparatus out of the heater casting 8 forinspection and repair.

At the top of the heater casting I provide a pyrex cylinder or sleeveI8. This sleeve is Jdared toward its upper end to receive a pyreXcontainer I9 iilled with magnesia.

The assembly, i. e., metal mass I, shell 3 and the heater casting 8, ispacked in inagnesia or other suitable heat insulation 2Q in a vacuum jar2 I, the latter being packed in heat insulating material 22 in a sealedcasing 23.

It will be seen from the drawing that the feedwater inlet and steamoutlet are brought through thetop of the casing or container 23.

The leads for the electric heating element are brought from the outsideof the apparatus and are designated 24 and 25, One ci these leads goesto the heating element direct, the other through` fusible Vlink 26 andthe thermostat oi Fig. 4 to the heating element.

This thermostat, which is a well known commercial article, comprises adisc 2l carrying contacts 28, cooperating wih contacts 29 on a bie-'metal disc 33.

The cold position of this dise is shown in dotted lines in Fig. 4. Whilethis therscribed, the thermostat will close to close the electriccircuit of the heating element.

To reduce the thermal conductivity o f the metal mass l adjacent Vthefeedwater inlet, I

groove thesame as shown at 3| and fill this V groove with asbestos,magnesia or other suitable' l tion of steam. That the apparatus whileautomatically controlled has no moving parts at all with the exceptionof the dished bimetal disc 3E, and that repairs and renewals are easilymade.

' It is to be understood that changes may be made in the details ofconstruction and arrangement of parts within the purview of myinvention. l

What-I claim is:-

1. An .electric steam generator comprising in combination a metal masswith a heater cast therein, said mass being provided with a centralchamber, a metal shell tting said chamber, and a second Ymetal massprovided with a grooved periphery fitting within said shell, thesaid'groove Vin conjunction with said shell providing evaporatingsurfaces for the generation of steam.

2. An electric steam generator comprising in combination V,aV metal masswith a heater cast therein, said mass being provided with a centralchamber, a metal shell fitting said chamber, and a second metal massprovided with a grooved Y periphery fitting within said shell, the saidgroove in conjunction with said shell providing evaporating surfaces forthe generation of steam, said second metal mass being provided with acentral longitudinal passageway for the passage of steam upwardly of theapparatus.

3. An electric steam generator comprising in combination a metal masswith a heater' cast therein, said mass being provided with a centralchamber, a metal shell tting said chamber, and a second metal massprovided with a downwardly extending groove on its periphery fittingwithin said shell, the said groove in conjunction with said shellVproviding evaporating surfaces for the generation of steam. V

4. An electric steam generator comprising ,in combination a metal masswith va heater cast therein, a metal shell tting into a chamber in saidcasting, a second metal mass fitting into said shell, the periphery ofsaid second metal mass being provided with a groove extending helicallyabout its periphery and a feedwater inlet at the 1Lipper end of saidgroove, saidV shell and second metalmass being removable as a unit fromthe heater casting.

5. An electric steamV generator comprising in combination a metal masswith a heater cast therein, a metal shell fitting into said casting, a

. secondV metalmass with a grooved periphery tting into said shell, afeedwater inlet connectedY to the upper end of said groove, said secondmetal mass being provided with a passageway Vextending from bottom totop of the same, and

a steam outlet at the upper end of said passageway.

combination a metal mass with a heater cast therein, a metal shell ttinginto a chamber in said casting, a grooved second metal mass fit- 6. Anelectric steam generator comprising in` ting into said shell, afeedwater inlet at 'the upper end of said groovefand an automaticallyoper- Y extending downwardly and in conjunction with said shellproviding an evaporating surface, a passageway for steam extendingrfromthe bottom to the-top of said metal mass, a steam outlet connected tothe upper end of said passageway, a

thermostat adjacent the upper end of said metal mass forpcontrolling thecircuit of said heating element, and metal tubing constituting a feed-Vwater inlet coiled about said casting and connected to the upper end ofsaidrgroove.Y

8. An electric steam generator comprisingin combination a metal heatercasting, a heater element embedded therein, a metal shell tting intosaid casting, a Vmetal mass tting into said shell, the periphery of saidmetal mass being p-rovided with a helically extending groove coperatingwith said shell to provide an evaporating surface, a double walled topfor said shell,

said walls being 'spaced apart to provide a passageway for feedwatercommunicating with said evaporating surface, and a thermostat forcontrolling the circuit of said heater located immediately above theupper of said walls, whereby admission of feedwater to the apparatuswill soY effect operation or" said thermostat to close the circuit ofthe heater element. Y

9. An electric steam generator comprising in combination a heatercasting, a metal shell fitting into said casting, a metal mass ttinginto said shell, said metal mass being provided with a helicallyextending groove in its periphery, the said groove cooperating with saidshell to provide an evaporating surface, said mass being provided with apassageway extending from bottom= to top of said metal mass, thelower'end of said passageway communicatingV withY said evaporating sur-Y face, a thermostat adjacent the upper end of the apparatus andsupported thereby for controlling the electric circuit of theheater,said thermostat, metal mass and shell being removable as a unit.

10.r An electric steam generator comprising in combination a metal masswitha heater cast therein, said mass being providedwith a centralchamber, a metal shell fitting said chamber, and a second metal massprovided with a grooved k periphery fitting within said shell, the saidgroove in conjunction with said shell providing evaporating surfaces forthe generation of steam, heat insulation for said apparatus and anenclosing vacuum jar. l Y

11. An electric steam generator comprising in combination a metal masswith a heater cast therein, a metal shell fitting into a chamber in saidcasting, a grooved second metal mass fitting into said shell, afeedwater inlet at the upperV end of said groove, an automaticallyoperable control device adjacent the feedwater inlet for controlling theelectric circuit of the heater, and

a fuse operable to open the circuit of the heater on an excessivetemperature rise in the apparatus.

Y KURT BEYRODT.

